Add a struct for Interface information, update the test URDF

hardware_interface/include/hardware_interface/components/component_info.hpp

@@ -24,6 +24,27 @@ namespace hardware_interface
 namespace components
 {
 
+/**
+ * \brief This structure stores information about components defined for a specific hardware
+ * in robot's URDF.
+ */
+struct InterfaceInfo
+{
+  /**
+   * \brief name of the command interfaces that can be set, e.g. "position", "velocity", etc.
+   * Used by joints.
+   */
+  std::string name;
+  /**
+   * \brief (optional) minimal allowed values of the interface.
+   */
+  std::string min;
+  /**
+   * \brief (optional) maximal allowed values of the interface.
+   */
+  std::string max;
+};
+
 /**
  * \brief This structure stores information about components defined for a specific hardware
  * in robot's URDF.
@@ -46,14 +67,14 @@ struct ComponentInfo
    * \brief name of the command interfaces that can be set, e.g. "position", "velocity", etc.
    * Used by joints.
    */
-  std::vector<std::string> command_interfaces;
+  std::vector<InterfaceInfo> command_interfaces;
   /**
    * \brief name of the state interfaces that can be read, e.g. "position", "velocity", etc.
    * Used by Joints and Sensors.
    */
-  std::vector<std::string> state_interfaces;
+  std::vector<InterfaceInfo> state_interfaces;
   /**
-   * \brief (optional) key-value pairs of components parameters.
+   * \brief (optional) key-value pairs of component parameters, e.g. min/max values or serial number.
    */
   std::unordered_map<std::string, std::string> parameters;
 };

hardware_interface/include/hardware_interface/components/joint.hpp

@@ -50,26 +50,36 @@ class Joint
    * return_type::ERROR otherwise.
    */
   HARDWARE_INTERFACE_PUBLIC
-  virtual
   return_type configure(const ComponentInfo & joint_info);
 
   /**
    * \brief Provide the list of command interfaces configured for the joint.
-   *
-   * \return string list with command interfaces.
+   * \return vector of command interface names.
    */
   HARDWARE_INTERFACE_PUBLIC
-  virtual
-  std::vector<std::string> get_command_interfaces() const;
+  std::vector<std::string> get_command_interface_names() const;
+
+  /**
+   * \brief Provide the list of command interfaces configured for the joint.
+   * \return vector of command interfaces.
+   */
+  HARDWARE_INTERFACE_PUBLIC
+  std::vector<InterfaceInfo> get_command_interfaces() const;
+
+  /**
+   * \brief Provide the list of state interfaces configured for the joint.
+   * \return vector of state interface names.
+   */
+  HARDWARE_INTERFACE_PUBLIC
+  std::vector<std::string> get_state_interface_names() const;
 
   /**
    * \brief Provide the list of state interfaces configured for the joint.
    *
    * \return string list with state interfaces.
    */
   HARDWARE_INTERFACE_PUBLIC
-  virtual
-  std::vector<std::string> get_state_interfaces() const;
+  std::vector<InterfaceInfo> get_state_interfaces() const;
 
   /**
    * \brief Get command list from the joint. This function is used in the write function of the
@@ -78,16 +88,16 @@ class Joint
    * provide.
    *
    * \param command list of doubles with commands for the hardware.
-   * \param interfaces list of interfaces on which commands have to set.
+   * \param interfaces list of interface names to retrieve from.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if command and interfaces arguments do not
    * have the same length; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
    * defined for the joint; return return_type::INTERFACE_NOT_PROVIDED if the list of interfaces
    * is empty; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_command(
-    std::vector<double> & command, const std::vector<std::string> & interfaces) const;
+    std::vector<double> & command,
+    const std::vector<std::string> & interfaces) const;
 
   /**
    * \brief Get complete command list for the joint. This function is used by the hardware to get
@@ -98,7 +108,6 @@ class Joint
    * \return return_type::OK always.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_command(std::vector<double> & command) const;
 
   /**
@@ -107,7 +116,7 @@ class Joint
    * of elements. Using the interfaces list, the controller can choose which values to set.
    *
    * \param command list of doubles with commands for the hardware.
-   * \param interfaces list of interfaces on which commands have to be provided.
+   * \param interfaces list of interface names on which commands have to be provided.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if command and interfaces arguments do not
    * have the same length; return_type::COMMAND_OUT_OF_LIMITS if one of the command values is out
    * of limits; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
@@ -118,9 +127,9 @@ class Joint
    * (see: https://github.com/ros-controls/ros2_control/issues/129)
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_command(
-    const std::vector<double> & command, const std::vector<std::string> & interfaces);
+    const std::vector<double> & command,
+    const std::vector<std::string> & interfaces);
 
   /**
    * \brief Get complete state list from the joint. This function is used by the hardware to get
@@ -133,7 +142,6 @@ class Joint
    * of limits; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_command(const std::vector<double> & command);
 
   /**
@@ -142,14 +150,13 @@ class Joint
    * number of elements. Using the interfaces list, the controller can choose which values to get.
    *
    * \param state list of doubles with states of the hardware.
-   * \param interfaces list of interfaces on which states have to be provided.
+   * \param interfaces list of interface names to provide for.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if state and interfaces arguments do not
    * have the same length; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
    * defined for the joint; return return_type::INTERFACE_NOT_PROVIDED if the list of interfaces
    * is empty; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_state(
     std::vector<double> & state,
     const std::vector<std::string> & interfaces) const;
@@ -163,7 +170,6 @@ class Joint
    * \return return_type::OK always.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_state(std::vector<double> & state) const;
 
   /**
@@ -172,15 +178,15 @@ class Joint
    * the interfaces list, the hardware can choose which values to set.
    *
    * \param state list of doubles with states of the hardware.
-   * \param interfaces list of interfaces on which states have to be provided.
+   * \param interfaces list of interface names to provide for.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if state and interfaces arguments do not
    * have the same length; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
    * defined for the joint; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_state(
-    const std::vector<double> & state, const std::vector<std::string> & interfaces);
+    const std::vector<double> & state,
+    const std::vector<std::string> & interfaces);
 
   /**
    * \brief Set complete state list from the joint.This function is used by the hardware to set its
@@ -192,7 +198,6 @@ class Joint
    * joint's state interfaces, return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_state(const std::vector<double> & state);
 
 protected:

hardware_interface/include/hardware_interface/components/sensor.hpp

@@ -50,34 +50,40 @@ class Sensor
    * return_type::ERROR otherwise.
    */
   HARDWARE_INTERFACE_PUBLIC
-  virtual
   return_type configure(const ComponentInfo & joint_info);
 
+  // TODO(andyz): implement this
+  /**
+   * \brief Provide the list of state interfaces configured for the joint.
+   * \return vector of state interface names.
+   */
+  HARDWARE_INTERFACE_PUBLIC
+  std::vector<std::string> get_state_interface_names() const;
+
   /**
    * \brief Provide the list of state interfaces configured for the sensor.
    *
-   * \return string list with state interfaces.
+   * \return list of state interfaces.
    */
   HARDWARE_INTERFACE_PUBLIC
-  virtual
-  std::vector<std::string> get_state_interfaces() const;
+  std::vector<components::InterfaceInfo> get_state_interfaces() const;
 
   /**
    * \brief Get state list from the sensor. This function is used by the controller to get the
    * actual state of the hardware. The parameters state, and interfaces have the same order and
    * number of elements. Using the interfaces list, the controller can choose which values to get.
    *
    * \param state list of doubles with states of the hardware.
-   * \param interfaces list of interfaces on which states have to be provided.
+   * \param interfaces list of interface names to provide for.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if state and interfaces arguments do not
    * have the same length; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
    * defined for the sensor; return return_type::INTERFACE_NOT_PROVIDED if the list of interfaces
    * is empty; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_state(
-    std::vector<double> & state, const std::vector<std::string> & interfaces) const;
+    std::vector<double> & state,
+    const std::vector<std::string> & interfaces) const;
 
   /**
    * \brief Get complete state list from the sensor. This function is used by the controller to get
@@ -88,7 +94,6 @@ class Sensor
    * \return return_type::OK always.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type get_state(std::vector<double> & state) const;
 
   /**
@@ -97,15 +102,15 @@ class Sensor
    * the interfaces list, the hardware can choose which values to set.
    *
    * \param state list of doubles with states of the hardware.
-   * \param interfaces list of interfaces on which states have to be provided.
+   * \param interfaces list of interface names to provide for.
    * \return return_type::INTERFACE_VALUE_SIZE_NOT_EQUAL if state and interfaces arguments do not
    * have the same length; return_type::INTERFACE_NOT_FOUND if one of provided interfaces is not
    * defined for the sensor; return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_state(
-    const std::vector<double> & state, const std::vector<std::string> & interfaces);
+    const std::vector<double> & state,
+    const std::vector<std::string> & interfaces);
 
   /**
    * \brief Set complete state list from the sensor.This function is used by the hardware to set its
@@ -117,7 +122,6 @@ class Sensor
    * sensor's state interfaces, return_type::OK otherwise.
    */
   HARDWARE_INTERFACE_EXPORT
-  virtual
   return_type set_state(const std::vector<double> & state);
 
 protected:

hardware_interface/src/component_parser.cpp

@@ -34,6 +34,8 @@ constexpr const auto kSensorTag = "sensor";
 constexpr const auto kTransmissionTag = "transmission";
 constexpr const auto kCommandInterfaceTypeTag = "commandInterfaceType";
 constexpr const auto kStateInterfaceTypeTag = "stateInterfaceType";
+constexpr const auto kMinTag = "min";
+constexpr const auto kMaxTag = "max";
 }  // namespace
 
 namespace hardware_interface
@@ -64,7 +66,7 @@ std::string get_text_for_element(
  * If attribute is not found throws an error.
  *
  * \param element_it XMLElement iterator to search for the attribute
- * \param attribute_name atribute name to serach for and return value
+ * \param attribute_name attribute name to search for and return value
  * \param tag_name parent tag name where attribute is searched for (used for error output)
  * \return attribute value
  * \throws std::runtime_error if attribute is not found
@@ -88,7 +90,7 @@ std::string get_attribute_value(
  * If attribute is not found throws an error.
  *
  * \param element_it XMLElement iterator to search for the attribute
- * \param attribute_name atribute name to serach for and return value
+ * \param attribute_name atribute name to search for and return value
  * \param tag_name parent tag name where attribute is searched for (used for error output)
  * \return attribute value
  * \throws std::runtime_error if attribute is not found
@@ -132,22 +134,51 @@ std::unordered_map<std::string, std::string> parse_parameters_from_xml(
 /**
  * \brief Search XML snippet for definition of interfaceTypes.
  *
- * \param interfaces_it pointer to the interator over interfaces
+ * \param interfaces_it pointer to the iterator over interfaces
  * \param interfaceTag interface type tag (command or state)
  * \return std::vector< std::__cxx11::string > list of interface types
  * \throws std::runtime_error if the interfaceType text not set in a tag
  */
-std::vector<std::string> parse_interfaces_from_xml(
+std::vector<components::InterfaceInfo> parse_interfaces_from_xml(
   const tinyxml2::XMLElement * interfaces_it, const char * interfaceTag)
 {
-  std::vector<std::string> interfaces;
+  std::vector<components::InterfaceInfo> interfaces;
 
   while (interfaces_it) {
-    const std::string interface_type = get_text_for_element(
-      interfaces_it, std::string(interfaceTag) + " type ");
-    interfaces.push_back(interface_type);
+    hardware_interface::components::InterfaceInfo interface;
+
+    // Joint interfaces have a name attribute
+    if (std::string(interfaceTag) == "commandInterfaceType") {
+      const std::string interface_name = get_attribute_value(
+        interfaces_it, "name",
+        std::string(interfaceTag));
+      interface.name = interface_name;
+
+      // Optional min/max attributes
+      std::unordered_map<std::string, std::string> interface_params =
+        parse_parameters_from_xml(interfaces_it->FirstChildElement(kParamTag));
+      std::unordered_map<std::string, std::string>::const_iterator interface_param =
+        interface_params.find(kMinTag);
+      if (interface_param != interface_params.end()) {
+        interface.min = interface_param->second;
+      }
+      interface_param = interface_params.find(kMaxTag);
+      if (interface_param != interface_params.end()) {
+        interface.max = interface_param->second;
+      }
+    }
+    // State interfaces have an element to define the type, not a name attribute
+    if (std::string(interfaceTag) == "stateInterfaceType") {
+      const std::string interface_type = get_text_for_element(
+        interfaces_it,
+        std::string(interfaceTag) + " type ");
+      interface.name = interface_type;
+    }
+
+    interfaces.push_back(interface);
     interfaces_it = interfaces_it->NextSiblingElement(interfaceTag);
   }
+
   return interfaces;
 }